The not_null_tables() of Item_func_not_all and Item_in_optimizer was inherited from
Item_func by mistake. It made the optimizer think that subquery
predicates with ALL/ANY/IN were null-rejecting. This could trigger invalid
conversions of outer joins into inner joins.
mysql-test/suite/innodb/t/group_commit_crash.test:
remove autoincrement to avoid rbr being used for insert ... select
mysql-test/suite/innodb/t/group_commit_crash_no_optimize_thread.test:
remove autoincrement to avoid rbr being used for insert ... select
mysys/my_addr_resolve.c:
a pointer to a buffer is returned to the caller -> the buffer cannot be on the stack
mysys/stacktrace.c:
my_vsnprintf() is ok here, in 5.5
This bug appeared after the patch for bug 939009 that in the
function merge_key_fields forgot to reset a proper value for
the val field in the result of the merge operation of the key
field created for a regular key access and the key field
created to look for a NULL key.
Adjusted the results of the test case for bug 939009 that
actually were incorrect.
IS EXECUTED TWICE FROM P
This bug is a duplicate of bug 12567331, which was pushed to the
optimizer backporting tree on 2011-06-11. This is just a back-port of
the fix. Both test cases are included as they differ somewhat.
sql/sql_insert.cc:
CREATE ... IF NOT EXISTS may do nothing, but
it is still not a failure. don't forget to my_ok it.
******
CREATE ... IF NOT EXISTS may do nothing, but
it is still not a failure. don't forget to my_ok it.
sql/sql_table.cc:
small cleanup
******
small cleanup
of the 5.3 code line after a merge with 5.2 on 2010-10-28
in order not to allow the cost to access a joined table to be equal
to 0 ever.
Expanded data sets for many test cases to get the same execution plans
as before.
For any query JOIN::optimize() should call the method
SELECT::save_leaf_tables after the last transformation
that utilizes the statement memory rather than the
execution memory.
This bug is a special case of lp:813447.
Analysis:
Constant optimization finds that the condition t2.a = 1
can be used to access the primary key of table 't2'. As
a result both outer table t1,t2 are considered as constant
when we reach the execution phase. At the same time, during
constant optimization, the IN predicate is not evaluated
because it is expensive.
When execution of the outer query reaches do_select(),
control flow enter the branch:
if (join->table_count == join->const_tables)
{ ... }
This branch checks only the WHERE and HAVING clauses,
but doesn't check the ON clauses of the query. Since the
IN predicate was not evaluated during optimization, it is
not evaluated at all, thus execution doesn't detect that
the ON clause is FALSE.
Solution:
Similar to the patch for bug lp:813447, exclude system
tables from constant substitution based on unique key
lookups if there is an expensive ON condition on the
inner table.
in combination with IS NULL'
As this bug is a duplicate of bug#49322, it also includes test cases
covering this bugreport
Qualifying an OUTER JOIN with the condition 'WHERE <column> IS NULL',
where <column> is declared as 'NOT NULL' causes the
'not_exists_optimize' to be enabled by the optimizer.
In evaluate_join_record() the 'not_exists_optimize' caused
'NESTED_LOOP_NO_MORE_ROWS' to be returned immediately
when a matching row was found.
However, as the 'not_exists_optimize' is derived from
'JOIN_TAB::select_cond', the usual rules for condition guards
also applies for 'not_exist_optimize'. It is therefore incorrect
to check 'not_exists_optimize' without ensuring that all guards
protecting it is 'open'.
This fix uses the fact that 'not_exists_optimize' is derived from
a 'is_null' predicate term in 'tab->select_cond'. Furthermore,
'is_null' will evaluate to 'false' for any 'non-null' rows
once all guards protecting the is_null is open.
We can use this knowledge as an implicit guard check for the
'not_exists_optimize' by moving 'if (...not_exists_optimize)'
inside the handling of 'select_cond==false'. It will then
not take effect before its guards are open.
We also add an assert which requires that a
'not_exists_optimize' always comes together with
a select_cond. (containing 'is_null').
Item_equal::val_int() checked for NULL-values by checking Item::null_value
*before* the respective ::store_value() and ::cmp(Item*) metods where called.
As Item::null_value is set by these metods, the value of 'null_value'
is not valid until *after* ::store_value() or ::cmp() has
been called for the Item object.
Fix is to swap order of ::store_value()/::cmp() and checking of Item::null_value.
This pattern is widely used other places inside item_cmpfunc.cc .
The patch also fixes a race in rpl_stop_slave.test.
On machines with lots of CPU and memory, something like `mtr --parallel=10`
can speed up the test suite enormously. However, we have a few test cases
that run for long (several minutes), and if we are unlucky and happen to
schedule those towards the end of the test suite, we end up with most
workers idle while waiting for the last slow test to end, significantly
delaying the finish of the entire suite.
Improve this by marking the offending tests as taking "long", and trying
to schedule those tests early. This reduces the time towards the end of
the test suite run where some workers are waiting with nothing to do for
the remaining workers each to finish their last test.
Also, the rpl_stop_slave test had a race which could cause it to take
a 300 seconds debug_sync timeout; this is fixed.
Testing on a 4-core 8GB machine, this patch speeds up the test suite with
around 30% for --parallel=10 (debug build), allowing to run the entire
suite in 5 minutes.
- Fixed problem with oqgraph and 'make dist'
Note that after this merge we have a problem show in join_outer where we examine too many rows in one specific case (related to BUG#57024).
This will be fixed when mwl#128 is merged into 5.3.
Open issues:
- A better fix for #57688; Igor is working on this
- Test failure in index_merge_innodb.test ; Igor promised to look at this
- Some Innodb tests fails (need to merge with latest xtradb) ; Kristian promised to look at this.
- Failing tests: innodb_plugin.innodb_bug56143 innodb_plugin.innodb_bug56632 innodb_plugin.innodb_bug56680 innodb_plugin.innodb_bug57255
- Werror is disabled; Should be enabled after merge with xtradb.
Lines below which were added in the patch for Bug#56814 cause this crash:
+ if (table->table)
+ table->table->maybe_null= FALSE;
Consider following test case:
--
CREATE TABLE t1(f1 INT NOT NULL);
INSERT INTO t1 VALUES (16777214),(0);
SELECT COUNT(*) FROM t1 LEFT JOIN t1 t2
ON 1 WHERE t2.f1 > 1 GROUP BY t2.f1;
DROP TABLE t1;
--
We set TABLE::maybe_null to FALSE for t2 table
and in create_tmp_field() we create appropriate tmp table field
using create_tmp_field_from_item() function instead of
create_tmp_field_from_field. As a result we have
LONGLONG field. As we have GROUP BY clause we calculate
group buffer length, see calc_group_buffer().
Item from group list which is used for calculation
refer to the field from real tables and have LONG type.
So group buffer length become insufficient for storing of
LONGLONG value. It leads to overwriting of wrong memory
area in do_field_int() function which is called from
end_update().
After some investigation I found out that
create_tmp_field_from_item() is used only for OLAP
grouping and can not be used for common grouping
as it could be an incompatibility between tmp
table fields and group buffer length.
We can not remove create_tmp_field_from_item() call from
create_tmp_field as OLAP needs it and we can not use this
function for common grouping. So we should remove setting
TABLE::maybe_null to FALSE from simplify_joins().
In this case we'll get wrong behaviour of
list_contains_unique_index() back. To fix it we
could use Field::real_maybe_null() check instead of
Field::maybe_null() and add addition check of
TABLE_LIST::outer_join.
mysql-test/r/group_by.result:
test case
mysql-test/r/join_outer.result:
test case
mysql-test/t/group_by.test:
test case
mysql-test/t/join_outer.test:
test case
sql/sql_select.cc:
--remove wrong code
--use Field::real_maybe_null() check instead of
Field::maybe_null() and add addition check of
TABLE_LIST::outer_join
Employed the same kind of optimization as in the fix for the cases
when join buffer is used.
The optimization performs early evaluation of the conditions from
on expression with table references to only outer tables of
an outer join.
The condition over the outer tables now are extracted from
the on condition of any outer join. This condition is
saved in a special field of the JOIN_TAB structure for
the first inner table of the outer join. The condition
is checked before the first inner table is accessed. If
it turns out to be false the table is not accessed at all
and a null complemented row is generated immediately.
The problem could be demonstrated with an outer join of two single-row
tables where the values of the join attributes were null. Any query
with such a join could return a wrong result set if the where
condition of the query was not empty. For queries with empty
where conditions the result sets were correct.
This was the consequence of two bugs in the code:
- Item_equal objects for on conditions of outer joins were
not built if the processed query had no where condition
- the check for null values in the code that evaluated constant
Item_equal objects was incorrect.
Fixed both above problems.
Added a test case for the bug and adjusted results for some other
test cases.
There are two problems:
1. In simplify_joins function we calculate table dependencies. If STRAIGHT_JOIN hint
is used for whole SELECT we do not count it and as result some dependendecies
might be lost. It leads to incorrect table order which is returned by
join_tab_cmp_straight() function.
2. make_join_statistics() calculate the transitive closure for relations a particular
JOIN_TAB is 'dependent on'.
We aggregate the dependent table_map of a JOIN_TAB by adding dependencies from other
tables which we depend on. However, this may also cause new dependencies to be
available after we have completed processing a certain JOIN_TAB.
Both these problems affect condition pushdown and as result condition might be pushed
into wrong table which leads to crash or even omitted which leads to wrong result.
The fix:
1. Use modified 'transitive closure' algorithm provided by Ole John Aske
2. Update table dependences in simplify_joins according to
global STRAIGHT_JOIN hint.
Note: the patch also fixes bugs 46091 & 51492
mysql-test/r/join_outer.result:
test case
mysql-test/t/join_outer.test:
test case
sql/sql_select.cc:
1. Use modified 'transitive closure' algorithm provided by Ole John Aske
2. Update table dependences in simplify_joins according to
global STRAIGHT_JOIN hint.
greedy_search optimizer_search_depth=0
The algorithm inside restore_prev_nj_state failed to
properly update the counters within the NESTED_JOIN
tree. The counter was decremented each time a table in the
node was removed from the QEP, the correct thing to do being
only to decrement it when the last table in the child node
was removed from the plan. This lead to node counters
getting negative values and the plan thus appeared
impossible. An assertion caught this.
Fixed by not recursing up the tree unless the last table in
the join nest node is removed from the plan
Optimizer erroneously translated LEFT JOIN into INNER JOIN.
It leads to cutting rows with NULL right side. It happens
because Item_row uses not_null_tables() method form the
base(Item) class and does not calculate 'null tables'
properly. The fix is adding calculation of 'not null tables'
to Item_row.
mysql-test/r/join_outer.result:
test result
mysql-test/t/join_outer.test:
test case
sql/item_row.cc:
adding calculation of 'not null tables' to Item_row.
sql/item_row.h:
adding calculation of 'not null tables' to Item_row.
returns incorrect results with where
An outer join of a const table (outer) and a normal table
(inner) with GROUP BY on a field from the outer table would
optimize away GROUP BY, and thus trigger the optimization to
do away with a temporary table if grouping was performed on
columns from the const table, hence executing the query with
filesort without temporary table. But this should not be
done if there is a non-indexed access to the inner table,
since filesort does not handle joins. It expects either ref
access, range ditto or table scan. The join condition will
thus not be applied.
Fixed by always forcing execution with temporary table in
the case of ROLLUP with a query involving an outer join. This
is a slightly broader class of queries than need fixing, but
it is hard to ascertain the position of a ROLLUP field wrt
outer join with current query representation.
mysql-test/r/join_outer.result:
Bug#47650: Test result
mysql-test/t/join_outer.test:
Bug#47650: Test case
sql/sql_select.cc:
Bug#47650: Fix
into gleb.loc:/home/uchum/work/bk/mysql-5.1-opt
client/mysqldump.c:
Auto merged
mysql-test/r/join_outer.result:
Auto merged
mysql-test/r/kill.result:
Auto merged
mysql-test/r/view.result:
Auto merged
mysql-test/t/join_outer.test:
Auto merged
mysql-test/t/kill.test:
Auto merged
sql/field.h:
Auto merged
sql/item_func.cc:
Auto merged
sql/sp_head.cc:
Auto merged
sql/sql_base.cc:
Auto merged
mysql-test/r/mysqldump.result:
Merge with 5.0-opt
mysql-test/t/mysqldump.test:
Merge with 5.0-opt
mysql-test/t/view.test:
Merge with 5.0-opt
sql/sql_select.cc:
Merge with 5.0-opt
constant outer tables did not return null complemented
rows when conditions were evaluated to FALSE.
Wrong results were returned because the conditions over constant
outer tables, when being pushed down, were erroneously enclosed
into the guard function used for WHERE conditions.
mysql-test/r/join_outer.result:
Added a test case for bug #28571.
mysql-test/t/join_outer.test:
Added a test case for bug #28571.
sql/sql_select.cc:
Fixed bug #28571. Outer join queries with ON conditions over
constant outer tables did not return null complemented
rows when conditions were evaluated to FALSE.
Wrong results were returned because the conditions over constant
outer tables, when being pushed down, were erroneously enclosed
into the guard function used for WHERE conditions.
The problem is fixed in the function make_join_select. Now the
conditions over constant tables from ON expressions are pushed
down after the conditions from WHERE has been pushed down.
into magare.gmz:/home/kgeorge/mysql/work/B27531-5.1-opt
mysql-test/r/cast.result:
Auto merged
mysql-test/r/join_outer.result:
Auto merged
mysql-test/t/cast.test:
Auto merged
mysql-test/t/join_outer.test:
Auto merged
sql/item_func.cc:
Auto merged
sql/item_subselect.cc:
Auto merged
sql/sql_parse.cc:
Auto merged
sql/sql_select.cc:
Auto merged
sql/sql_select.h:
Auto merged
mysql-test/r/subselect.result:
merge of 5.0-opt -> 5.1-opt
mysql-test/t/subselect.test:
merge of 5.0-opt -> 5.1-opt
